Diazotype recording process and material used therein

ABSTRACT

DIAZO COPYING PROCESS USING AS THE COUPLING AGENT A THAIAZOLIUM COMPOUND CORRESPONDING TO THE FOLOWING GENERAL FORMULA:   2-CH3,3-R1,4-R2,5-R3-THIAZOLIUM X(-)   WHEREIN: X-REPRESENTS AN ANION AND MAY BE MISSING WHEN THE ANION IS PRESENT IN THE R1 GROUP, R1 REPRESENTS AN ORGANIC GROUP INTRODUCED BY QUATERNIZATION, EACH OF R2 AND R3 REPRESENTS AND ALKY GROUP OR AN ARYL GROUP AND ONLY ONE OF R2 AND R3 IS HYDROGEN; AND RECORDING MATERIALS USEFUL THEREIN. A PREFERRED THIAZOLIUM COMPOUND IS 2,3-DIMETHYL-THIAZOLIUM ETHYLTOLUSULPHONATE AND A PREFERRED DIAZONIUM COMPOUND IS P-DIEHYLAMINOBENZENE-DIAZONIUM TETRABOROFLUORIDE.

United States Patent 1 3,676,133 Patented July 11, 1972 hce /69 Int. Cl. G03c 1/58, 5/22, 5/34 US. CI. 96-49 Claims ABSTRACT OF THE DISCLOSURE Diazo copying process using as the coupling agent a thiazolium compound corresponding to the following general formula: I

R3 S CH3] 1 l Rj N+Ri X- represents an anion and may be missing When the anion is present in the R group,

R represents an organic group introduced by quaternization, each of R and R represents an alkyl group or an aryl group and only one of R and R is hydrogen; and recording materials useful therein.

A preferred thiazolium compound is 2,3-dimethyl-thiazolium ethyltolusulphonate and a preferred diazoniurn compound is p-diethylaminobenzene-diazonium tetraborofluoride.

wherein:

This invention relates to recording and reproduction of information and to the use of particular chemical compounds in the diazo recording process.

As is known the diazo recording process is based on the fact that certain diazo compounds, eg diazonium salts, can be decomposed information-wise by light under nitrogen evolution and remaining diazo compound can react with a so-called coupler to form a dye.

In the dry diazo process, also called two-component diazo system, the recording material contains a diazo compound and a coupler. In addition, it contains an acid that prevents the premature reaction of the diazo compound and the coupler. After the recording material is exposed to ultra-violet light passing through the original, it is treated With a volatile base such as ammonia. This neutralizes the acid and allows the remaining diazo compound to combine with the coupler and to form a dye in the image areas.

In the wet or moist diazo process, also called onecomponent diazo system, the recording material contains only the diazo compound. After the recording material is exposed image-wise to ultra-violet, it is treated with an alkaline solution containing the coupler. The remaining diazo compound couples with the coupler in the nonexposed areas.

A coupler in the broader definition is a substance that bears an active or mobile hydrogen atom.

Normally used couplers are aromatic hydroxy compounds such as phenols and naphthols of which 2,3-dihydroxynaphthalene-6-sulphonic acid is a typical example.

Other known couplers contain a reactive methyl, or methylene group as described in the Belgian patent specification 459,543 filed Aug. 3, 1945 by Gevaert Photo- Production N.V. and United States patent specification 2,532,744 of James M. Straley, issued Dec. 5, 1950. Typical examples of the latter class are quaternary salts of 2- methylquinoline, 2-methyl thiazole and 2-methyl-benzothiazole and N-methyl-2-methylene-benzothiazoline.

We have found that active methyl couplers represented by the following general structure can be used to produce diazotype materials with good shelf life and still high coupling speed for the formation of green to violet dyes;

s CHa X- represents an anion eg, a chloride, bromide, iodide, perchlorate, thiocyanate, benzene sulphonate, p-toluene sulphonate, methyl sulphate, ethyl sulphate or a propyl sulphate anion, but X- is missing when the anion is already contained in the R group (betaine salt form), e.g.

as a

R represents an organic group introduced by quaternization, e.g. an aliphatic group, including a cycloaliphatic group, a saturated aliphatic group, an unsaturated aliphatic group or one of said groups in substituted form, e.g. an alkyl groups, more particularly a C -C alkyl group, an allyl group, a cycloalkyl group, e.g. a cyclopentyl or cyclohexyl group, a substituted cycloalkyl group, a substituted alkyl group, e.g. a hydroxyalkyl group, a carboxyalkyl group, a sulphoalkyl group, a sulphatoalkyl group, a phosphoalkyl group, a phosphoester substituted alkyl group, an acetoxyalkyl group, wherein the substituted alkyl group preferably contains from 1 to 4 carbon atoms, such as in fi-hydroxyethyl, B-acetoxyethyl, sulphopropyl, sulphobutyl, phosphopropyl, sulphato propyl, and sulphato butyl, further the substituted alkyl group wherein M is hydrogen, an onium group or a metal atom, B represents a lower alkylene group such as a methylene, ethylene, propylene or butylene group, and A represents a methylene group or group, (examples of such substituted alkyl group are described in the United Kingdom patent specification 886,271 filed June 20, 1957 by Gevaert-Photo-Producten N.V., e.g. a sulphocarbomethoxymethyl group, an w-Slllphocarbopropoxymethyl group, a p (w sulphocarbobutoxybenzyl group), and further the substituted alkyl group -A WNHV-B wherein A represents a lower alkylene group such as a methylene, ethylene, propylene or butylene group, B, represents an alkyl group, an amino group, a substituted amino group and also a hydrogen atom in the case V is a single bond, and W and V each represent a --CO-radical, a SO radical or a single bond but at least one of them is a -SO radical, (examples of such substituted alkyl groups are described in the United Kingdom patent specification 904,332 filed July 5, 1957 by Gevaert Photo-Producten N.V., e.g. a N-(methylsulphonyl)-carbamylmethyl group, a -(acetyl sulphamyl)-propyl; or a 6-(acetylsulphamyl)- butyl group), or an aromatically substituted alkyl group, e.g. a benzyl group, a phenylethyl group, a substituted aralkyl group, e.g. a hydroxybenzyl group, a carboxybenzyl group, a sulphobenzyl group, a halogenated benzyl group, e.g. a bromobenzyl group, and

Each of R and R represents hydrogen, an alkyl group including a substituted alkyl group e.g. a C -C alkyl group preferably a methyl group, an ethyl group or a chloromethyl group, an aryl group including a substituted aryl group e.g. a phenyl group, a biphenyl group or a methoxyphenyl group, the thiazolium nucleus being free from R =hydrogen when R =hydrogen, and vice-versa.

Thiazolium compounds are known as starting materials for the preparation of methine dyes suited for the spectral sensitization of photographic silver halide emulsions. References to the preparation of preferred thiazolium compounds are given in conjunction with Table 2 further on.

In the photographic reproduction process according to the present invention the thiazolium compounds are allowed to couple with diazo compounds. Such diazo compounds are diazonium salts that can optionally be produced from diazo sulphonates. The diazonium salts suitable for use according to the present invention can be defined as aromatic compounds bearing a diazo group, of which one valency is satisfied by a carbon atom from the aromatic nucleus and the other valency by an acidic ion.

Particularly suitable diazonium compounds are the stabilized diazonium salts, preferably the zinc chloride double salts and fluoroborates.

Exemplary diazonium salts are those prepared by diazotization of amines listed in Table 1.

TABLE 1 1) p-amino-N,N-dimethylaniline (2) p-amino-N,N-diethylaniline (3 p-amino-N-ethyl-N-B-hydroxyethylaniline (4) p-amino-N-ethyl-N-benzylaniline 3O (5) p-amino-phenylmorpholine 6) pamino- (2,5 -diethoxy) -N-benzoylaniline (7) p-amino-(2,5-dibutoxy)N-benzylaniline (8) 4-amino-(2,5-dimethoxy)-4'-methyldiphenyl sulphide 4 (9) p-amino-o-ethoXy-N,N-diethylaniline (10) p-amino-o-chloro-N,N-diethylaniline Diazonium compounds that are preferably used for obtaining green and violet dyes by coupling with the thiazolium compounds of the general formula are prepared by diazotization of primary aromatic amines that in paraposition with respect to the primary amino group contain a tertiary amino group such as a dialkylamino group, wherein the alkyl groups may be substituted.

Particularly useful in View of that purpose are the diazonium compounds corresponding to the following structural formulae:

CH:CH5OH a (diazo 11) In the following Table 2, thiazolium compounds that are particularly suited for use according to the present invention are listed with their melting point and the colour of the dye obtained by coupling with the diazonium salt diazo 69.

]B Fr (diazo 69) CzHs TABLE 2 S R oH3 l R:- N+'Rl Number Melting of the Colour of the point, coupler R R R; X- dye C.

1- (32H; CH H I Green.. 269

2 CzHs CH3 H d0..--..-..- 86

E S O;

3-. HO 0 O I OH: H Br do 260 4 01115 f H I do 172 5. CzHs Q E I do 280 6........- (32115 H CH3 1 -.-(l0

7 CZHB CH3 CH3 --...d0 Oil H03 S 0;

TABLE 2lC0nrtinued S R9 CH3 l l Rr- N+ i Melting il i e Colour of the point, coupler R1 R2 R; X dye C.

8-. CH3 I CH3 I do 185 9--. C2115 H I I Violet 129 I 0 CH;

10.....-..-- CaHu CICH: H 3 -.d0 260 11 C 115 C1011: H Violet-black. 260

can I l Violet 186 13..."... cant I l -.-.-do on 14.--.--" 01H: H l I do 154 Couplers No. 1 and 2 can be prepared according to a method described in the French patent specification 757,- 768 filed June 29, 1933 by Eastman Kodak. Couplers No. 3 and 4 can be prepared according to methods described in the German patent specification 908,346 filed June 6, 1942 by Gevaert 'Photo-Producten NV. and the French patent specification 739,314 filed June 30, 1932 by Eastman Kodak, respectively.

Coupler No. 5 can be prepared according to E. D. Sych, Ukrain. Khim. Zhur. 22, 80 (1956).

Coupler No. 7 can be prepared according to T. Takahashi & M. Hayami, Yakagaku Zasshi, 81, 1419 (1961).

Coupler No. 6 can be prepared analogously to compound 7.

Coupler No. 8 can be prepared according to J. L. B. Smith, J. Chem. Soc. 1923, 2288.

Coupler No. 9 can be prepared according to Belgian patent specification 652,320 filed Aug. 26, 1964 by DuPont de Nemours.

Couplers No. 12 and 13 can be prepared according to US. patent specification 2,148,441 of G. A. Dawson and E. B. Middleton, issued Feb. 28, 1939.

Coupler No. 14 can be prepared according to E. D. Sych, Ukrain. Khim. Zhur. 22, 217 (1956) 27, '83 (1961).

Suitable supports or layers used in copying materials according to the present invention have liquid-absorbing characteristics, as e.g., ordinary Wood pulp paper or rag type paper but also textiles including fabrics made of cotton, cellulose acetate, regenerated cellulose, in other words all types of Woven or felted materials, which can be impregnated with a solution containing one or more of the diazonium compounds and/ or couplers may be used.

For producing transparent diazo prints a transparent sheet is used as support, e.g. a Water-impermeable resin sheet. In that connection reference is made to transparent film-supports of use in silver halide photography. When using a Water-impermeable resin sheet as support the imaging chemicals are preferably applied into a hydrophilic colloid layer e.g., a gelatiu-containing layer.

The radiation sensitive coating composition containing a diazonium compound may contain all kinds of other ingredients, e.g. wetting agents, substances generating a base on heating or a material releasing base on heating, e.g. urea and the substances used for that purpose described, e.g., in the United Kingdom patent specification 983,363 filed May 8, 1961 by Nashua Corp. and the French patent specifications 1,376,708 and 1,376,709 both filed Sept. 17, 1963 by Et. Bauchet et Co., further optical brightening agents, pigments, e.g. silica, and antioxidants improving the whiteness of the areas, in which the diazonium compound has been destroyed. Suitable antioxidants are thiourea, ascorbic acid and allyl isothiocyanate in concentrations ranging from 15 to 25 percent by Weight in respect of the diazonium salts.

"Preferred amounts of diazonium compound and coupler per sq. m. are in the range of 0.1 g. to 0.5 g. and 0.1 g. to 1.5 g. respectively.

A good storage stability of a coating composition containing a diazonium compound and a coupler according to the general formula can be obtained by using in admixture with said compounds an acid, e.g. citric acid, tartaric acid, boric acid, trichloroacetic acid, tribromoacetic acid, sulphosalicylic acid, phosphoric acid or 1,3,6-naphthalenetrisulphonic acid disodium salt in an amount of 100 to 200 percent by weight in respect of the diazonium salt.

Obviously all known principles for preventing premature coupling can be applied in order to obtain a recording material with a storage stability as high as possible. In that connection is mentioned, e.g., the keeping out of direct contact of the diazonium compound and the coupler by means of a meltable layer or capsule envelope.

The following examples illustrate the present invention.

EXAMPLE 1 A coating composition was prepared by mixing the following ingredients until dissolution of the Water-soluble compounds:

p-diethylaminobenzene-diazonium-tetraborofiuoride (diazo 6'9)6 g.

2,3-dimethyl-thiazolium ethyltolusulphonate-S g.

citric acid40 g.

naphthalene-trisulphonic acid trisodium salt-8 g.

25% aqueous solution of naphthalene-trisulphonic acid disodium salt56 ml.

urea-20 g.

colloidal silica-1 g.

saponine0.5 g.

water up to-400 ml.

The composition was coated onto a white paper base in a proportion of 19 g. per sq. m. and after drying through a line diapositive exposed with ultraviolet light in a common diazotype copying apparatus.

The development proceeded by leading the exposed material through ammonia vapour.

A green positive print on a clean white background was obtained.

Under the same conditions the couplers 9-l4 of Table 2 yielded violet positive images.

EXAMPLE 2 A photographic cellulose triacetate base provided with a subbing layer on the basis of gelatin was coated with the following composition: diazo 6910 g. 10% by weight aqueous solution of perchloric acid 75 ml. 2,3-dimethyl-thiazolium ethyl-tolusulphonate-IO g. saponine-0.5 g. n-propanol-IOO ml. 0.5% by weight aqueous gelatin solution-320 ml.

Coating proceeded in a proportion of 30 g. per sq.m. Exposure and development were the same as described in Example 1.

A green positive transparent copy of the original was obtained.

EXAMPLE 3 Instead of diazo 69 as described in Example 1 a same amout of diazo 8 was used.

A same green print on a clean white background was obtained.

EXAMPLE 4 Instead of diazo 69 as described in Example 1 a same amount of diazo 11 was used.

A same green print on a clean white background was obtained.

We claim:

1. A method for recording and reproducing information which comprises the steps of decomposing informationwise a diazo compound and allowing to react remaining diazo compound with a thiazolium compound corresponding to the following general formula:

wherein:

X represents an anion, but is missing when the anion is already contained in the R group,

R represents an organic group introduced by quaternization, each of R and R represents hydrogen, an alkyl group including a substituted alkyl group, or an aryl group including a substituted aryl group, the thiazolium nucleus being free from hydrogen in the 5-position when in the 4-position R is hydrogen and vice-versa.

2. A method according to claim 1, wherein the thiazolium compound is used in a dry diazo process.

3. A method according to claim 1, wherein the thiazolium compound is used in a wet diazo process.

4. A method according to claim 1, wherein a diazo compound is used that has been prepared by diazotization of a primary aromatic amine, which in para-position with respect to the primary amino group contains a tertiary amino group.

5. A method according to claim 4, wherein the diazonium salt is of the Zinc chloride double salt or fluoroborate type.

6. A method according to claim 5, wherein the diazonium salt corresponds to one of the following structural formulae:

7. A diazotype recording material containing a diazo compound that is decomposable by irradiation with ultraviolet light and a thiazolium compound corresponding to the following general formula:

X- represents an anion, but is missing when the anion is already contained in the R group,

R represents an aliphatic group including a cycloaliphatic group, a saturated aliphatic group, an unsaturated aliphatic group or one of said groups in substituted form,

each of R and R represents hydrogen, an alkyl group including a substituted alkyl group, or an aryl group including a substituted aryl group, the thiazolium nucleus being free from hydrogen in the 5-position when in the 4-position R is hydrogen and vice-versa.

8. A diazotype recording material according to claim 7, wherein the diazo compound has been prepared by diazotization of a primary aromatic amine, which in paraposition with respect to the primary amino group contains a tertiary amino group.

9. A diazotype recording material according to claim 7 or 8, wherein the diazonium compound is of the zinc chloride double salt or fluoborate type.

10. A diazotype recording material according to claim 9, wherein the diazonium compound corresponds to one of the following structural formulae:

References Cited UNITED STATES PATENTS NORMAN G. TORCHIN, Primary Examiner 20 J. L. GOODROW, Assistant Examiner U.S. C1. X.R. 

